A casualty is the damage, destruction, or loss of property resulting from an identifiable event that is sudden, unexpected, or unusual. 1  A sudden event is one that is swift, not gradual or progressive. 2  An unexpected event is one that is ordinarily unanticipated and unintended.
exists and is an alternate of . The noble gas notation is a notation formed as a result of the electron configuration notation being used in conjunction with noble gases. The noble gas preceding the element in question is written then the electron configuration is continued from that point onwards. The notation is shorter to write and makes it easier to identify elements.
The only chemical elements which are stable single atom molecules at standard temperature and pressure (STP), are the noble gases. These are helium, neon, argon, krypton, xenon and radon. The heavier noble gases can form chemical compounds, but the lighter ones are non-reactive or inert. For example, helium, being the simplest noble gas, has only two electrons, thus meaning it is satisfied with a complete outer shell, making it relatively non-reactive, hence it is a noble gas.